Iron Grip: The Oppression v1.3 Client

* ADD - IG_Locomotive: A Rahmos train is attacked by Resistance fighters who must kill the General while he's cornered.
* ADD - IG_Dynadares: A large port city where Rahmos and Resistance battle for territorial control.
* ADD - Gameplay entity: Allows mappers to designate their own objectives depending on how the map should be played
* ADD - New audio: Map sounds for Locomotive, weapon sounds, and new